The invention generally relates to a catheter, more particularly to a catheter for angiographic uses. Included is a tube-like basic body with a distal end and a proximal end for connection to a proximal end hub or the like for grasping, manipulating and controlling the catheter. At the proximal end, the catheter is provided with a flexible portion which, when in use, can be bent in a controlled manner from the proximal end. The catheter can also include a strip-like electrode which is a helically wound wire.
In order to bend the distal end portion of a catheter in a controlled manner, it is known to make use of a guidewire with a tip bent in a specific shape which is advanced to the end portion by way of the channel of the catheter. By rotation or lengthwise shifting of the guidewire in relation to the catheter, a deflection of the end-section is achieved. In that respect, the deflection can be oriented in any radial direction of the catheter.
Catheters having deflecting tips are also shown in U.S. Pat. No. 5,125,896 and European Patent Publication No. 361,314 (No. 9301018). In such catheters, a pull wire is included within the body of the catheter. When such wire is pulled, the distal end portion of the catheter bends in a somewhat arcuate manner. However, this deflection is not directly controlled or easily adjustable. In addition, when electrodes are included in these types of catheters, they are typically in the form of tip electrodes or ring electrodes that require generally conventional assembly arrangements.
The invention provides a controlled flexible catheter wherein the deflection always takes place in the same, known radial direction, so that for instance an electrode situated on the side of the catheter can be manipulated carefully into a desired position, for instance touching the wall of a blood vessel or of the heart. With the catheter according to the invention, this is achieved by fixing a pull wire, extending through the catheter in a secure manner. Preferably, the pull wire is fixed eccentrically, and the distal end portion of the catheter bends towards the side where the pull wire is fixed when the pull wire is pulled. Typically, the pull wire can be manufactured in a simple fashion and is securely engaged in a reliable manner within the end portion of the catheter, such as in a hook-like manner.
In an important aspect of the invention, a comparatively stiff sliding wire stiffens the distal end portion into which it extends, so that bending occurs at substantially only that part of the distal end portion into which the sliding wire does not extend. Advancing or withdrawing movement of the sliding wire adjusts the shape and length of the deflecting distal portion to the amount desired by the physician.
The invention is especially suitable for use with a strip-shaped electrode and/or heating element extending longitudinally in the wall of the flexible distal end portion of the catheter. Because of the controlled deflection of the distal end portion of the catheter, the entire length of this strip-shaped electrode can be placed carefully, for example against the wall of a ventricle, in order to locally heat and/or ablate tissue when treating certain types of cardiac arrhythmias. To assure adequate flexibility of the distal end portion of the catheter, the strip-shaped electrode assembly includes a helically wound wire which is very pliable and forms the strip-shaped electrode by means of the adjoining, uncovered windings of the strip-shaped electrode. A lateral side of this helically wound wire is situated at the surface of the end-section of the catheter to generally define the strip-shaped electrode.
It is a general object of this invention to provide an improved controlled flexible catheter.
Another object of the present invention is to provide an improved controlled catheter which achieves controlled flexing of its distal tip portion in an adjustable manner.
Another object of this invention is to provide an improved controlled flexible catheter which can be manipulated into a specific position, such as to orient an electrode thereof directly onto a desired location of a vessel wall or chamber.
Another object of the present invention is to provide an improved controlled flexible catheter by which proper and careful manipulation of the catheter is achieved by having a physician hold its proximal-end handle in one hand and operate a control assembly with a few fingers of the same hand.
Another object of this invention is to provide an improved controlled flexible catheter that exhibits a strip-like electrode which is an integral portion of a helically wound wire.
Another object of the present invention is to provide an improved controlled flexible catheter utilizing a pull wire which is securely and simply affixed at its distal end.
These and other objects, features and advantages of this invention will be clearly understood through a consideration of the following detailed description.